The aegis & intelligencer. [volume] (Bel Air, Md.) 1864-1923, 1887-11-04
SURVEYING DIFFICULT IN HAIR
FORD COUNTY.
A Meridian Line should be Established
on the Fair Ground


For The LEgis and Inteligencer
AS land becomes more valuable, the uncert-
amy OF the magnetic needle as dependence in
tnls section VIII be fully recognized. Local at
traction, swaying the needle from the smallest
fraction of a degree, up 10 six or eight de-
grces, Is almost everywhere present, go that
the magnetic bearing ola given line, depends
upon the point on that line where you place
your instrument. Again the secular change
OF from three to five minutes year-adds a
great and ever recurring difficulty in the re.
survey ofold lines. 1t is often impossible 10
Tx the date of the previous survey, as the
date OF the deed is generally not the date of
the survey, your particular decd having been
| copied from previous deed of the same pro-
perty, and perhaps that from another Sum
up these difficulties and the exact rCsuryey of
an unmarked old line becomes cXtremelydif
ncut. You may go to some marked line on
The same farm for your variation by COM
parison, but you cannot put your instrument
down where the previous surveyor did, and
local attraction gives you IN erroneous varia-
ZION: Surveyors generally understand all this,
out 1t is singular fact that very few ofthem
acknowledge ii; they would impress their en-.
pioyers that there is some peculiar charm in
their skill On tiIcif Instrument which erahles
them 10 run to the exact point every time
The evil of this quaCkcry in surveyors is
to make landowners careless OF their land
marks and neglectful ofplacing stones on all
their boundaries, and thus originates many a
wasteful lawsuit.
Angular instruments are made to take in
cluded angles or angles Of DETECTION and TO
make a survey without the use of the needle.
For the convenient and accurate use of these
instruments, the lines must he more carefully
cleared than for the use ofthe magnetic needle,
but the angle is taken TO the last minute,
While in the use of the needle readings ofnot
less than fifteen minutes are rarely made.
These instruments are always furnished with
a delicate needle to be used at pleasure, and
the mean magnetic bearing of single line.
taken at several points on that line. NAV be
used as q basis to figure from the included
angles the magnetic bearing of the remain
ing lines ofthc farm, whether for record or
Tor calculation by the ordinary traverse table.
vi course these instruu ents are not adapt
ed to resurvey magnetic surveys, but all new
lines established by included angles could be
resurVeyed with great certainty if any mark
ed line could be found on the farm, as both
local attraction and secular variation would
be perfectly thrust aside.
hear that in Canada, and perhaps in some
sections OF the States, they have made the
use OF these instruments necessary by law
Necessarily all city surveying is done with
angular instruments, the masses of iron in
the gas and water pipes, and in the lamp
posts, rendering the magnetic needle useless.
Owing to the mineral in the soil surveying
here in Hartford is not unlike city surveying.
All the real estate of Hartford county has
been surveyed and described by magnetic
bearings, and where stones mark the lermi-
nations of the lines, perfectly straight lines
can be run from boundary to boundary, but
when this is done these lines will not pass
where the ordinary surveyor runs them
Moving on from point to point without back
sights, as his needle directs him, he is certain
to make an angle smaller or greater every
time he places his instrument. This is not
the theory of non-eXperience, but it is the
statement of one who has surveyed here in
Hartford more than thirty years from first 10
last, with intervals of the the same work in
other counties and States.
Doubtless the magnetic needle will be used
here in Hartford for many years TO come In
decd any Others system can be introduced only
gradually. Now what can be done to i'm
prove the present very imperfect and careless
method lfin every deed after the descrip-
ton of the land, the date of the survey were
stated If every surveyor would begin his field
notes with statement of the date, date his
description and his plais, one source of
error would be partially removed. An
error OF ten years in the date of q
survey, throws Che termination of line
a mile long, 46 is feet from its true place, and
this, at the usual allowance of three minutes
per year variation, while from observations
that l am now making am led to believe
that the north end ofthe needle is moving
to the west more than five minutes per year,
at this place. Further there should be q
correctly established meridian line of length
not less than forty perches, that surveyors
may test their instruments at least once
year, or before making any important survey,
and in their notes and plats state the varia.
ton of their needles, and if after the date of
the survey in every deed, the magnetic
variation were stated then perfectly accu-
rate start at u resurVey could be made, and
the only obstacles would be carelessness in
the first survey, and local attraction
An excellent location for such meridian
line would be on the fair ground fixing its
south terminus at a stone that WAS very per-
manently set at the centre of the south
curve. A true north and south line
of between forty and fifty perchcs in length
could be there located. The longer the line
the more accurate the observation by MAX
ing new beginning still longer line could
there be located. G. G. CuRTIss